Grantee Research Project Results
2024 Progress Report: Multimedia Measurement of PFAS in the Residential Environment: Evaluating Human Exposure Pathways
EPA Grant Number: CR840428Title: Multimedia Measurement of PFAS in the Residential Environment: Evaluating Human Exposure Pathways
Investigators: Hoffman, Kate , Bartell, Scott M. , Stapleton, Heather , Peaslee, Graham , Vieira, Veronica
Institution: Duke University , University of Notre Dame , University of California - Irvine
EPA Project Officer: Packard, Benjamin H
Project Period: July 1, 2022 through May 9, 2025
Project Period Covered by this Report: July 1, 2023 through June 30,2024
Project Amount: $248,180
RFA: COLLECTION OF CONCORDANT MULTIMEDIA MEASUREMENTS TO EVALUATE PFAS HUMAN EXPOSURE PATHWAYS (2021) RFA Text | Recipients Lists
Research Category: Urban Air Toxics , Endocrine Disruptors , Heavy Metal Contamination of Soil/Water , Drinking Water , Human Health , Air , PFAS Treatment , Environment
Objective:
Widespread exposure to per- and polyfluoroalkyl substances (PFAS) has been documented in the US population. Considerable research has identified drinking water as a significant source of PFAS exposure, particularly in areas proximal to contaminated sites. However, recent data also link exposure with the indoor environment. PFAS are commonly detected in indoor air and dust, suggesting these exposure pathways may be particularly relevant for the general population. However, investigations of exposure via the indoor environment are limited. This study aims to address this data gap by evaluating PFAS in the residential environment and estimating its contribution to total PFAS exposure in the general population. We proposed to 1) Characterize total organic fluorine (TOF) in indoor air and dust, evaluating variation within the home and potential PFAS sources (e.g., carpet and textiles) and 2) Assess the relative contributions of PFAS measured in drinking water and the indoor environment in determining human PFAS exposure. Approach: We partnered with the UCI PFAS Health Study, a CDC/ATSRD Multi-site Study cohort based in Orange County, California, to efficiently and rigorously address our aims. Collection of blood and urine from UCI PFAS Health Study participants is underway and drinking water wells in the study area have been tested for PFAS quarterly since 2019. We proposed to complement these existing data sources with additional collection of paired passive indoor air samples (3 per home) and dust samples (3 per home) from 50 participants’ homes. Participants will also wear a silicone wristband for 21 days to capture exposure across multiple microenvironments. Samples will be evaluated for PFAS as well as TOF, a marker of PFAS. Variation in TOF within a home will be assessed statistically and evaluated in relation to products present in the home. We will identify the relative importance of drinking water, diet, and indoor exposure routes (air and dust) in determining PFAS body burdens, investigating the relationship between each matrix and serum. Expected Outcomes: Successful completion of our aims will address key questions on the most relevant PFAS exposure pathways for the general US population. Specifically, we will determine how much variability in PFAS serum levels in this study population is explained by water consumption and residential sources and will assess variation due to other sources (e.g., diet and product use), which is a critical first step in designing exposure reduction strategies and policies. In addition, we will evaluate the minimal set of measurements that can be implemented to classify individual exposure levels and determine whether silicone wristbands are sufficient to capture residential exposure information needed to estimate PFAS exposure. Advances in exposure assessment have important implications for identifying vulnerable populations and efficiently evaluating exposure for future health impacts studies.
Progress Summary:
Our project aims to fill gaps in understanding PFAS exposure by evaluating its presence in residential environments and estimating its contribution to total PFAS exposure in the general population. Despite initial delays due to regulatory processes, we have made significant progress, including receiving IRB approval and finalizing a data transfer agreement between Duke and UCI. We began enrolling participants from the UCI PFAS Health Study in March 2024, with 45 of 50 participants recruited. We completed both home visits for 33 participants and anticipate finishing all visits by October 2024. Sample analysis for PFAS has begun. Additionally, we are conducting secondary analysis of data from a cohort of toddlers in North Carolina to compare PFAS exposure between children and adults.
Future Activities:
We expect to complete all home visits and data collection by October 2024. Sample analysis is already underway, and we plan to finalize all analyses (TOF and PFAS) by January 2025. Following this, our team will focus on statistical analysis and the dissemination of results through presentations and manuscripts.
Supplemental Keywords:
air, dust, silicone wristbands, human exposure, poly- and perfluoroalkyl substances, PFAS, total fluorine, TOFProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.